Circular loom



Aug. 13, 1935. w. R. M EWAN El AL 2,011,154

CIRCULAR LOOM Filed June 12, 1935 w 2/ z; f /f/ l Z0 I g fA/VEN 7' E6 52 Macewa/z ZZZ, MiZZcL Patented Aug. 13, 1935 ill iarn Robertson MacEwan andJiilio lzaguirre Villa, LondomEngland, assignors'to The Weavmg -Mac'liines .England 1 Company, Limited, London,

Y Applicationljune 12, 193$,Serial time75: 1:32

' In Great Britain October 14, 1932 enim: (c1. -13,9-16),

This invention relates to; circular "looms in which the warpshedlies substantially in a cylindrical surface or in a conical surface of acute angle, coaxially of a central axis of weaving.

5 Such a circular loom is described and claimed in the specification of prior British Patent No. 336,246. V

In the specification of prior British Patent No.

374,562 there is described and claimed a mechanism for forming and re-forming the warp shed inwhich healds or heddle frames extend radially beneath a reed-like annular frame constituting a shuttle track, and adjacent healds or heddle frames are connected together at what may be termed their outer ends by a wire or equivalent, passing around a pulley or the like, carried by a frame of the loom, and at their inner ends by a further wire or equivalent passing around a second pulley or the like, close to the central axis of weaving; motion being imparted to this loop by a single cam or eccentric, adapted to be rotated about the axis of weaving, to a plurality of followers, or to the strap or band, of which the inner connecting wires or equivalent of the healds or heddle frames are attached. With such an arrangement, considerable difficulty is experienced in forming what may be termed the heddle loops all of exactly the same size, so that the shed formation will becomespondingly even or symmetric all around the shuttle track; and the present invention has for an object toprovide improved heddle mechanism for forming and re-forming the warp shed and whereby this drawback may be avoided.

According to the invention, a single cam only, concentric with the central axis of weaving, is employed, and each of a plurality of followers of this cam is secured to, or is integral with, a primary rack mounted to reciprocate substantially radially of said axis, and the teeth of which mesh with a fixed pinion by which the primary rack is coupled operatively with the secondary rack, with the teeth of which said pinion also meshes; said secondary rack being mounted also 7 to reciprocate substantially radially of the axis of weaving and each primary and each secondary rack carrying a heald or heddlefr'ame.

It will be observed that in all cases the meshing of a coupling pinion with the teeth of the cor responding primary and secondary racks is such that when the one rack is at one extreme of its travel, so the other is at the opposite extreme of its travel- The invention is illustrated by the accompanyingdiagrammatic drawing, of which:

'1 Figure l is ajfragmentary viewshowing in part sectional side elevation one arrangement of a pair of primary and secondary racks, and associated parts of a circular loom;

Figure 2 being a corresponding plan view. 5

As shown in Figures 1 and 2, heddle mechanism comprises essentially a grooved face cam l I, rotatable about a central axis of weaving, a series of followers, of which one is indicated at [2 (Figure 1), engaging in the grooves [3 of the cam ll 10 and having attached thereto one end of a toothed primary rack it which, by guides l5 and I6, is constrained to reciprocate inwardly and outwardly radially of the central axis of weaving as the cam H is rotated. For each primary rack M, the teeth I! of which are, as shown, directed upwardly, a secondary rack I8 is mounted to reciprocate parallel therewith, the teeth I9 thereof being directed downwardly to mesh with a fixed pinion, indicated at 20, which, meshing also with the teeth ll of the primary rack l4, couples the two racks operatively together.

It will be seen that as the cam H is rotated, it will impart inward and outward movement to all the primary racks l4, and thus through the medium of these and the pinions 20, outward and inward movement to the secondary racks l8. As

above indicated, the racks l4 and I8 and the interconnecting pinions 20, are so assembled together that when, at any time being, one rack of each corresponding pair l4 and I8 is at a given point in its inward or outward travel, so the other rack of the pair will be at a corresponding point in its outward or inward travel.

Thus, each rack will have the motion it is necessary to impart to adjacent warp threads for the purpose of forming and re-forming the warp shed. According to the type of web which it is required to produce by a loom to which the heddle mechanism is fitted, each of the racks thereof will carry either a single heald or, as

shown, a heddle frame 2| or 22 of known or convenient type, the number of heddle frames being chosen to suit requirements.

Although it will in general be desirable to employ agrooved cam, as in the form of the invention just described, there may in some cases be employed either an eccentric or a cam which is capable of moving the follower positively in one direction only; said followers being spring-influenced to tend to move in the opposite direc tion. Any tendency for the cam followers themselves to rotate about the central axis of weaving may be obviated by the guides by which the primary racks are constrained to reciprocate radially.

In the case illustrated and as will in general be preferable, the heddle frames will be secured detachably to the respective racks so that different heddle frames may be used on the same loom when it is desired to produce difierentkinds of cloth. As shown, the heddle frames 2! and 22 have at their inner ends loops 23 and 24, respectively, adapted to be placed over-headed projeca tions 25 and 26 at the inner ends of the racks M and 38, respectively; and at their outer ends said heddle frames 2! and 22 have substantially L shaped metal fittings 21 and 28, respectively, adapted to mesh, as shown clearly in Figure l, with the teeth of the racks, and which are secured in this position by screws 29 and 30, re-/ spectively.

What we claim is: a

A heddle mechanism for a circular loom of a type wherein a single cam concentric with the axis of weaving is employed, a plurality of followers for the cam, a primary rack carried by each follower, a fixed pinion with which the teeth of said rack engage, a secondary rack meshing with said pinion and thereby coupled to the corresponding primary rack to provide a substantially exact phase of movement of both racks and a substantially exact uniformity in the throw of such racks, the secondary rack being reciprocated substantially radially of the axis of weaving, and a heald or heddle frame carried by each primary and each secondary rack, the substantially exact phase of movement and substantially exact uniformity in the throw of the racks insuring the maximum and uniform shed length progressively throughout the path of Weaving and substantially exact shed width in the progressive shed formations to thereby avoid the necessity for a margin of safety in shuttle length and thread capacity incident to flexible drives for the heddle frames in shed formation and permit a relatively increased size of shuttle with correspondingly increased thread capacity.

WILLIAM ROBERTSON MACEWAN. JULIO IZAGUIRRE VILLA. 

